Preparation method of plaster coating based on multi-stage filling and solid waste high-valued treatment

Abstract

The invention discloses a preparation method of a plaster coating based on multi-stage filling and solid waste high-value treatment. The preparation method specifically comprises the following steps: S1, high-value modification; s2, particle size selection; s3, preparing a dry blend; s4, preparing a wet mixed material; the invention relates to the technical field of building materials. According to the stucco coating preparation method based on multi-stage filling and solid waste high-valued treatment, the concept of minimum particle size is introduced through a Dinger-Funk equation, graded matching optimization of multi-stage filling is achieved, the void ratio is reduced, the solid waste mixing amount is increased through high-valued treatment of fly ash and sludge incineration residues, meanwhile, the stucco coating with high compressive strength is obtained, and the stucco coating with high compressive strength is obtained. And collaborative optimization of strength improvement, solid waste absorption and carbon emission reduction is realized.

Description

Technical Field

[0001] This invention relates to the field of building materials technology, specifically to a method for preparing mortar-based coatings based on multi-stage filling and high-value utilization of solid waste. Background Technology

[0002] Traditional stucco coatings have long relied on natural river sand as the main aggregate (accounting for 60-80%), and large-scale mining has led to riverbed erosion and ecosystem damage. At the same time, the carbon emissions from the production process of cement-based cementitious materials remain high, such as 0.6-0.9 tons of CO2 per ton of cement.

[0003] On the other hand, my country's industrial solid waste, such as fly ash and sludge incineration residue, has an annual discharge of more than 2 billion tons, with a comprehensive utilization rate of less than 30%. The large-scale accumulation of these wastes occupies land resources and poses a risk of heavy metal ion leakage.

[0004] Existing recycled aggregate coatings suffer from technical bottlenecks due to issues such as crude gradation design and insufficient solid waste activity, resulting in poor mechanical properties (e.g., 28-day compressive strength <10MPa), low freeze-thaw durability (e.g., mass loss >5% after 50 cycles), and weak construction adaptability.

[0005] In view of this, a method for optimizing the mix proportion of lime-based coatings based on multi-level gradation theory and high-value modification of solid waste is proposed to achieve synergistic optimization of strength improvement, solid waste disposal and carbon emission reduction. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a method for preparing ash-based coatings based on multi-stage filling and high-value utilization of solid waste, which solves the problems of low strength and insufficient solid waste utilization in traditional coatings.

[0007] To achieve the above objectives, the present invention provides a method for preparing silt-based coatings based on multi-stage filling and high-value utilization of solid waste, specifically comprising the following steps:

[0008] S1. High-value modification: Magnetic separation and acid washing are performed on sludge incineration residue to obtain modified sludge incineration residue, and alkali activation treatment is performed on fly ash to obtain alkali-activated fly ash.

[0009] S2. Particle Size Selection: The particle size range of the raw materials is screened using the Dinger-Funk equation. The raw materials include:

[0010] Primary skeleton: waste ceramic particles;

[0011] Secondary filler: modified sludge incineration residue;

[0012] Third-level cementitious material: alkali-activated fly ash;

[0013] Level 4 Density: Nano-silica;

[0014] S3. Preparation of dry mixture: Waste ceramic particles and modified sludge incineration residue are put into a twin-shaft mixer and mixed at 300 r / min for 5 min. White cement and activated fly ash are added and mixed at 600 r / min for 8 min. Nano silica is added and mixed at 800 r / min for 10 min to obtain dry mixture.

[0015] S4. Preparation of wet mixture: Add alkali activator and 25% water (by total mass of dry mixture) to dry mixture, stir at 800 r / min for 10 min, and degas under vacuum at -0.08 MPa for 15 min to obtain stucco coating.

[0016] The present invention is further configured such that the method for preparing the modified sludge incineration residue includes:

[0017] Iron removal from sludge incineration residue was achieved using a 1.2T magnetic field, followed by washing with 5wt% hydrochloric acid for 30 minutes and then washing with water until Cl was removed. - ≤0.03%.

[0018] The present invention is further configured such that the Dinger-Funk equation is:

[0019]

[0020] In the formula, P(D) is the cumulative sieve residue percentage for particles with a diameter ≤ D, and D is the target particle size in mm. min Minimum particle size, in mm, D max is the maximum particle size in mm, and q is the distribution coefficient, which is 0.45.

[0021] The present invention is further configured such that the method for preparing the alkali-activated fly ash includes:

[0022] Fly ash was mixed with 5 wt% sodium hydroxide solution at a mass ratio of 1:2, reacted in a water bath at 60℃ for 2 hours, separated by centrifugation, dried at 105℃, and ball-milled to 45 μm with a residue of ≤10% on a sieve.

[0023] The present invention is further configured such that the white cement, activated fly ash, modified sludge incineration residue, waste ceramic particles, nano silica and alkali activator are in the following mass ratio: 60:50:24:3:12.

[0024] The present invention is further configured such that: the alkaline activator comprises 3.5 wt% water glass and sodium hydroxide, wherein the mass ratio of water glass to sodium hydroxide is 3:1.

[0025] This invention provides a method for preparing silty mud coatings based on multi-stage filling and high-value utilization of solid waste. It has the following beneficial effects:

[0026] This invention introduces the concept of minimum particle size through the Dinger-Funk equation to achieve hierarchical matching optimization of multi-level filling, reduce porosity, and improve the solid waste content by high-value treatment of fly ash and sludge incineration residue. At the same time, it obtains high compressive strength ash-mud coating, achieving synergistic optimization of strength improvement, solid waste disposal and carbon emission reduction. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the method flow of the present invention. Detailed Implementation

[0028] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0029] Please see Figure 1 The present invention provides the following technical solution: a method for preparing silty mud coatings based on multi-stage filling and high-value utilization of solid waste, specifically including the following steps:

[0030] S1. High-value modification: Iron removal from sludge incineration residue was achieved by magnetic separation using a 1.2T magnetic field, followed by washing with 5wt% hydrochloric acid for 30 minutes, and then washing with water until Cl... - To obtain modified sludge incineration residue with a residue of ≤0.03%, fly ash and 5wt% sodium hydroxide solution are mixed at a mass ratio of 1:2, reacted in a water bath at 60℃ for 2 hours, separated by centrifugation, dried at 105℃, and ball-milled to 45μm. The residue on the sieve is ≤10%, thus obtaining alkali-activated fly ash, which increases the activity index of fly ash from the original 65% to 92%.

[0031] S2. Particle Size Selection: The particle size range of the raw materials is screened using the Dinger-Funk equation. The raw materials include:

[0032] Primary skeleton: waste ceramic particles;

[0033] Secondary filler: modified sludge incineration residue;

[0034] Third-level cementitious material: alkali-activated fly ash;

[0035] Level 4 density: Nano-silica.

[0036] The Dinger-Funk equation is as follows:

[0037]

[0038] In the formula, P(D) is the cumulative sieve residue percentage for particles with a diameter ≤ D, and D is the target particle size in mm. min Minimum particle size, in mm, D max is the maximum particle size in mm, and q is the distribution coefficient, which is 0.45.

[0039] The particle size of the raw materials is shown in Table 1:

[0040] Table 1

[0041] raw material Particle size range Target cumulative screening Waste ceramic particles 1-3mm P(3) = 100% Modified sludge incineration residue 0.15-1.18mm P(1.18)=65\%P(1.18)=65% Alkali-activated fly ash 0.045-0.15mm P(0.15)=30\%P(0.15)=30% Nano silica 0.0015-0.045mm P(0.045)=5\%P(0.045)=5%

[0042] The results of the formulation optimization are shown in Table 2:

[0043] Table 2

[0044] raw material Particle size range Waste ceramic particles 1-3mm Modified sludge incineration residue 0.15-1.18mm Alkali-activated fly ash ≤0.045mm Nano silica 0.0015±0.0005mm

[0045] S3. Preparation of dry mixture: 120 kg of waste ceramic particles and 200 kg of modified sludge incineration residue are put into a twin-shaft mixer and mixed at 300 r / min for 5 min. Then, 300 kg of white cement and 250 kg of activated fly ash are added and mixed at 600 r / min for 8 min. Finally, 15 kg of nano silica is added and mixed at 800 r / min for 10 min to obtain the dry mixture. The nano silica is added in three parts with an interval of 2 min between each addition.

[0046] S4. Preparation of wet mixture: Add 45 kg of 3.5 wt% water glass and 15 kg of sodium hydroxide as an alkali activator, and 25% of the total mass of the dry mixture as water to the dry mixture. Stir at 800 r / min for 10 min and degas under vacuum at -0.08 MPa for 15 min to obtain a stucco-based coating.

[0047] Performance testing

[0048] The obtained stucco-based coating was sprayed with an air compressor pressure of 0.6 MPa and a nozzle diameter of 3 mm. After natural curing for 7 days, the compressive strength, bond strength, and freeze-thaw mass loss were tested. The test results are shown in Table 3.

[0049] Table 3

[0050] index result Test Standards 28-day compressive strength 23.8MPa GB / T17671-2021 Bond strength 0.82MPa JG / T157-2009 50 freeze-thaw cycles and resulting mass loss 0.9％ GB / T50082-2009

[0051] In summary, this invention, by performing high-value treatment on sludge incineration residue and fly ash, and using the Dinger-Funk equation to calculate the four-level aggregate gradation, reduces the porosity, increases the amount of solid waste added, and improves the compressive strength of the coating. This not only solves the problems of low strength and high resource consumption of traditional coatings, but also achieves synergistic optimization of strength improvement, solid waste disposal, and carbon emission reduction.

[0052] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for preparing silty mud coatings based on multi-stage filling and high-value utilization of solid waste, characterized in that, Specifically, the following steps are included: S1. High-value modification: Magnetic separation and acid washing are performed on sludge incineration residue to obtain modified sludge incineration residue, and alkali activation treatment is performed on fly ash to obtain alkali-activated fly ash. S2. Particle Size Selection: The particle size range of the raw materials is screened using the Dinger-Funk equation. The raw materials include: Primary skeleton: waste ceramic particles; Secondary filler: modified sludge incineration residue; Third-stage cementitious material: alkali-activated fly ash; Level 4 density: Nano-silica; S3. Preparation of dry mixture: Waste ceramic particles and modified sludge incineration residue are put into a twin-shaft mixer and mixed at 300 r / min for 5 min. White cement and activated fly ash are added and mixed at 600 r / min for 8 min. Nano silica is added and mixed at 800 r / min for 10 min to obtain dry mixture. S4. Preparation of wet mixture: Add alkali activator and 25% water (by total mass of dry mixture) to dry mixture, stir at 800 r / min for 10 min, and degas under vacuum at -0.08 MPa for 15 min to obtain stucco coating.

2. The method for preparing ash-mud coatings based on multi-stage filling and high-value utilization of solid waste according to claim 1, characterized in that, The method for preparing the modified sludge incineration residue includes: Iron removal from sludge incineration residue was achieved using a 1.2T magnetic field, followed by washing with 5wt% hydrochloric acid for 30 minutes and then washing with water until Cl was removed. - ≤0.03%.

3. The method for preparing ash-mud coatings based on multi-stage filling and high-value utilization of solid waste according to claim 1, characterized in that, The Dinger-Funk equation is: In the formula, P(D) is the cumulative sieve residue percentage for particles with a diameter ≤ D, and D is the target particle size in mm. min Minimum particle size, in mm, D max is the maximum particle size in mm, and q is the distribution coefficient, which is 0.

45.

4. The method for preparing ash-mud coatings based on multi-stage filling and high-value utilization of solid waste according to claim 3, characterized in that, The method for preparing the alkali-activated fly ash includes: Fly ash was mixed with 5 wt% sodium hydroxide solution at a mass ratio of 1:2, reacted in a water bath at 60℃ for 2 hours, separated by centrifugation, dried at 105℃, and ball-milled to 45 μm with a residue of ≤10% on a sieve.

5. The method for preparing ash-mud-based coatings based on multi-stage filling and high-value utilization of solid waste according to claim 1, characterized in that, The white cement, activated fly ash, modified sludge incineration residue, waste ceramic particles, nano-silica, and alkali activator are present in a mass ratio of 60:50:24:3:

12.

6. The method for preparing ash-mud coatings based on multi-stage filling and high-value utilization of solid waste according to claim 1, characterized in that, The alkaline activator comprises 3.5 wt% water glass and sodium hydroxide, wherein the mass ratio of water glass to sodium hydroxide is 3:1.

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